According to a conventional technology, shown in Japanese Patent Publication Kokai 2000-252389, a chip 306 is adhered on a thin substrate 307. Wires 308 and 309 are bonded to the substrate 307. The substrate 307 is placed in a cavity of a molding die, and is resin-molded. In a resin-molding process, projections 312 are formed a bottom surface of the device. The projections 312 are used as electrodes. A metal layer covering the projections 312 is mechanical removed using a high-speed rotary knife or laser beam.
However, according to the above described conventional technology, the following disadvantage are found:
(1) Since a major part of the electrodes are made of resin, the electrodes have a high stiffness. As a result, bondability between the electrodes and substrate is deteriorated when thermal deformation is occurred on the substrate.
(2) Since BGA type of terminals are formed in a cutting process using a high-speed rotary knife or laser beam, bondability between the terminals and a substrate is deteriorated when such a cutting process is carried out. As a result, bonding wires may be broken.
(3) Since terminals must be divided into individuals, fabricating time is long and fabricating costs get higher.
(4) A substrate and resin mold have different thermal expansion rates, and therefore, a position and height of terminals are changed due to thermal contraction. As a result, the terminals may not be able to be bonded to the substrate.
(5) If a position and height of terminals are changed due to thermal contraction, an electric test for the semiconductor apparatus could not be carried out. That is because; test sockets or test terminals could not be contacted to the terminals of the semiconductor apparatus.
(6) It is impossible to form terminals for a semiconductor apparatus in which a voltage at a bottom surface of a semiconductor pellet.
(7) After a molding resin is hardened, the resin is thermally shrunk. Therefore, a stress is produced between terminals on a semiconductor pellet and terminals on a substrate. As a result, a disconnection may be occurred.